GIT-CHECK-REF-FOR(1)

NAME
git-check-ref-format - Ensures that a reference name is well formed

SYNOPSIS
git check-ref-format <refname>

DESCRIPTION
Checks if a given refname is acceptable, and exits with a non-zero status if it is not. A reference is used in git to specify branches and tags. A branch head is stored under the $GIT_DIR/refs/heads directory, and a tag is stored under the $GIT_DIR/refs/tags directory. git imposes the following rules on how references are named:

    1. They can include slash / for hierarchical (directory) grouping, but no slash-separated component can begin with a dot ..

    2. They cannot have two consecutive dots .. anywhere.

    3. They cannot have ASCII control characters (i.e. bytes whose values are lower than \040, or \177 DEL), space, tilde ~, caret ^, colon :, question-mark ?, asterisk *, or open bracket [ anywhere.

    4. They cannot end with a slash /.
These rules make it easy for shell script based tools to parse reference names, pathname expansion by the shell when a reference name is used unquoted (by mistake), and also avoids ambiguities in certain reference name expressions (see git-rev-parse(1)):

    1. A double-dot .. is often used as in ref1..ref2, and in some contexts this notation means ^ref1 ref2 (i.e. not in ref1 and in ref2).

    2. A tilde ~ and caret ^ are used to introduce the postfix nth parent and peel onion operation.

    3. A colon : is used as in srcref:dstref to mean "use srcref's value and store it in dstref" in fetch and push operations. It may also be used to select a specific object such as with 'git-cat-file': "git cat-file blob v1.3.3:refs.c".

GIT
Part of the git(1) suite